Depletion of PINK1 affects mitochondrial metabolism, calcium homeostasis and energy maintenance

作者：Heeman Bavo; Van den Haute Chris; Aelvoet Sarah Ann; Valsecchi Federica; Rodenburg Richard J; Reumers Veerle; Debyser Zeger; Callewaert Geert; Koopman Werner J H; Willems Peter H G M; Baekelandt Veerle^*

来源：Journal of Cell Science, 2011, 124(7): 1115-1125.

DOI：10.1242/jcs.078303

• Mitochondria
• Live cell imaging
• Parkinson's disease
• Lentiviral vector

Loss-of-function mutations in the gene encoding the mitochondrial PTEN-induced putative kinase 1 (PINK1) are a major cause of early-onset familial Parkinson's disease (PD). Recent studies have highlighted an important function for PINK1 in clearing depolarized mitochondria by mitophagy. However, the role of PINK1 in mitochondrial and cellular functioning in physiological conditions is still incompletely understood. Here, we investigate mitochondrial and cellular calcium (Ca2+) homeostasis in PINK1-knockdown and PINK1-knockout mouse cells, both in basal metabolic conditions and after physiological stimulation, using unbiased automated live single-cell imaging in combination with organelle-specific fluorescent probes. Our data reveal that depletion of PINK1 induces moderate fragmentation of the mitochondrial network, mitochondrial membrane depolarization and increased production of reactive oxygen species. This results in reduced uptake of Ca2+ by mitochondria after physiological stimulation. As a consequence, cells with knockdown or knockout of PINK1 display impaired mitochondrial ATP synthesis, which is exacerbated under conditions of increased ATP demand, thereby affecting cytosolic Ca2+ extrusion. The impairment in energy maintenance was confirmed in the brain of PINK1-knockout mice by in vivo bioluminescence imaging. Our findings demonstrate a key role for PINK1 in the regulation of mitochondrial homeostasis and energy metabolism under physiological conditions.

• 出版日期2011-4-1